接收函数方法估计Moho倾斜地区的地壳速度比
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摘要
造山带地区的复合力系作用往往使Moho界面发生变形,局部表现为倾斜状态.为了得到这些区域精确地壳速度比结构,本文基于H-κ方法发展了H-κ-θ方法.该方法不仅考虑了倾斜Moho层的响应,同时利用径向和切向接收函数信息,增加了对扫描的约束.利用该方法对青藏高原东南缘地壳厚度和速度比结构进行研究,结果表明:研究区内地壳明显存在不均匀性,松潘—甘孜地体平均地壳厚度约为60 km,四川盆地西缘约为47 km,扬子地台约为43 km,三江块体和扬子地台东南缘已接近正常地壳厚度;松潘—甘孜地体与扬子地台相邻部位地壳平均地震波速度比(V_p/V_s)普遍偏高,且四川盆地西侧发现一绕盆地边缘的弧形高V_p/V_s异常区(>1.88),我们推测该异常可能由青藏高原向东逃逸的地壳流体受到高强度的四川盆地阻挡,在其西侧堆积所致.
The Moho discontinuity is often deformed by complex forces in tectonic zones,which presents as a dipping Moho locally.In order to abtain acurate crustal V_p/V_s ratio for these regions,this paper proposed an H-κ-θ stacking method to estimate the crustal V_p/V_s and thickness,which considers the responses of a dipping Moho.Both radial and tangential receiver functions were stacked to improve the scanning precision.The results of its application to southeastern Tibet indicate that the crustal thickness beneath southeastern Tibet varied notably. The average crustal thickness is about 60 km,47 km and 43 km in Songpan-Garze fold system, Sichuan basin and Yangtze platform,respectively,with a normal value in Sanjiang fold zone and southeastern Yangtze platform.The crustal V_p/V_s ratio is higher in the region between the Songpan-Garze fold system and Yangtze platform,and is abnormally highest to the west of Sichuan basin (>1.88).We presume that the eastward crustal material flow was resisted by the Sichuan basin with high strength,and accumulated at west of Sichuan,consequently shows the unusual high V_p/V_s anomaly.
The Moho discontinuity is often deformed by complex forces in tectonic zones,which presents as a dipping Moho locally.In order to abtain acurate crustal V_p/V_s ratio for these regions,this paper proposed an H-κ-θ stacking method to estimate the crustal V_p/V_s and thickness,which considers the responses of a dipping Moho.Both radial and tangential receiver functions were stacked to improve the scanning precision.The results of its application to southeastern Tibet indicate that the crustal thickness beneath southeastern Tibet varied notably. The average crustal thickness is about 60 km,47 km and 43 km in Songpan-Garze fold system, Sichuan basin and Yangtze platform,respectively,with a normal value in Sanjiang fold zone and southeastern Yangtze platform.The crustal V_p/V_s ratio is higher in the region between the Songpan-Garze fold system and Yangtze platform,and is abnormally highest to the west of Sichuan basin (>1.88).We presume that the eastward crustal material flow was resisted by the Sichuan basin with high strength,and accumulated at west of Sichuan,consequently shows the unusual high V_p/V_s anomaly.
引文
[1] Royden L H,Burchfiel B C,King R W,et al.Surface deformation and lower crustal flow in eastern Tibet.Science, 1997,276:788～790
[2] 许忠淮.东亚地区现今构造应力图的编制.地震学报,2001,23(5) :492～501 Xu Z H.A present-day tectonic stress map for eastern Asia region.Acta Seismologica Sinica(in Chinese),2001,23(5) : 492～501
[3] Qin C,Papazachos C,Papadimitriou E.Velocity field for crustal deformation in China derived from seismic moment tensor summation of earthquakes.Tectono Physics,2002, 359:29～46
[4] 王琪,赖锡安,游新兆等.红河断裂的GPS监控与现代构造应力场.地壳变形与地震,1998,18(2) :49～56 Wang Q,Lai X A,You X Z,et al.GPS movement and present tectonic stress field in the Honghe fault,southwest China.Crustal Deformation and Earthquakes(in Chinese), 1998,18(2) :49～56
[5] Wang Q,Zhang P Z,Freymueller J T,et al.Present day crustal deformation in China constrained by global positioning system measurements.Science,2001,294:574～577
[6] 张培震,沈正康,王敏等.青藏高原及周边现今构造变形的运动学.地震地质,2004,26(3) :367～376 Zhang P Z,Shen Z K,Wang M,et al.Kinematics of present-day tectonic deformation of the Tibetan Plateau and its vicinities.Seismology and Geology(in Chinese),2004, 263:367～376
[7] Wang C Y,Chan W W,Mooney W D.Three-dimentional velocity structure of crust and upper mantle in southeastern China and its tectonic implications.J.Geophys.Res.,2003, 108(B9) ,2442,doi:10． 1029/2002JB001973
[8] Xu L L,Rondenay S,van der Hilst R D.Structure of the crust beneath the southeastern Tibetan Plateau from teleseismic receiver functions.Phys.Earth Planet.Int., 2007,165:176～193
[9] Owens T J,Zandt G.Implications of crustal property variations for models of Tibetan plateau evolution.Nature, 1997,387:37～43
[10] 滕吉文,张中杰,王光杰等.喜马拉雅碰撞造山带的深层动力过程与陆-陆碰撞新模型.地球物理学报,1999,42(4) :481～495 Teng J W,Zhang Z J,Wang G J,et al.The deep internal dynamical processes and new model of continental continental collision in Himalayan collision orogenic zone.Chinese J.Geophys.(in Chinese),1999,42(4) :481～495
[11] 刘启元,Rainer Kind,李顺成.中国数字地震台网的接收函数及其非线性反演.地球物理学报,1 997,40(5) :356～368 Liu Q Y,Rainer Kind,Li S C.The receiver functions at the stations of the Chinese Digital Seismic Network(CDSN)and their nonlinear inversion.Chinese J.Geophys.(Acta Geophysica Sinica)(in Chinese),1997,40(5) :356～368
[12] 吴庆举,曾融生,赵文津.喜马拉雅-青藏高原的上地幔倾斜构造与陆-陆碰撞过程.中国科学(D辑),2004,34(10) :919～925 Wu Q J,Zeng R S,Zhao W J.Upper mantle dipping tectonics and continent continent collision process in Himalayan-Tibet.Science in China(Set.D)(in Chinese),2004,34(10) :919～925
[13] 段永红,张先康,刘志等.阿尼玛卿缝合带东段地壳结构的接收函数研究.地震学报,2007,29(5) :483～491 Duan Y H,Zhang X K,Liu Z,et al.Crustal structure using receiver function in the east part of Anyemaqen suture belt. Acta Seismologica Sinic(in Chinese),2007,29(5) :483～491
[14] Burchfiel B C,Chen Z,Liu Y,et al.Tectonics of the Longmen Shan and adjacent regions.Int.Geol.Rev.,1996． 37:661～735
[15] King R W,SHEN Feng,Bruchfiel B C,et al.Geodetic measurement of crustal motion in southwest China.Geology,1997,25,1279～1282
[16] Chen Z,Burchfiel B C,Liu Y,et al.Global positioning system measurements from eastern Tibet and their implications for India/ Eurasia intercontinental deformation.J.Geophys.Res.,2000,105(B7) :16215～16227
[17] Shen F,Royden L H,Burchfiel B C.Large-scale crustal deformation of Tibetan Plateau.J.Geophys.Res.,2001,106:6793～6816
[18] Lev E,Long M D,van der Hilst R D.Seismic anisotropy in Eastern Tibet from shear wave splitting reveals changes in lithospheric deformation.Earth Planet.Sci.Lett.,2006,251:293～304
[19] Flesch L M,Holt W E,Silver P G,et al.Constraining the extent of crust-mantle coupling in central Asia using GPS,geologic,and shear-wave splitting data.Earth Planet.Sci.Lett.,238(1/2) :248～268
[20] 熊熊,滕吉文.青藏高原东缘地壳运动与深部过程的研究.地球物理学报,2002,45(4) :507～514 Xiong X,Teng J W.Study on crustal movement and deep process in eastern Qinghai-Xizang Plateau.Chinese J.Geophys.(in Chinese),2002,45(4) :507～514
[21] 吴乾蕃,祖金华,谢毅真等.云南地区地热基本特征.地震地质,1988,10(4) :177～183 Wu Q F,Zu J H,Xie Y Z.Basic geothermal characteristics in Yunnan Province.Seismol.Geol.(in Chinese),1988,10(4) :177～183
[22] 熊熊,谢厚泽,滕吉文.青藏高原物质东流力学背景探讨.地壳形变与地震,2001,21(2) :1～7 Xiong X,Xie H Z,Teng J W.Investigation for the mechanical background of the mass eastern flow in Tibetan Plateau.Crustal Deformation and Earthquakes(in Chinese),2001,21(2) :1～7
[23] 孙洁,徐常芳,江钊等.滇西地区地壳上地幔电性结构与地壳构造活动的关系.地震地质,1989,11(1) :35～45 Sun J,Xu C F,Jiang Z,et al.The electrical structure of the crust and upper mantle in the west part of Yunnan provinec and its relation to crustal tectonics.Seismol.Geol.(in Chinese),1989,11(1) :35～45
[24] 李立,金国元.攀西地区岩石圈的电性结构.见:中国攀西裂谷文集(3) .北京:地质出版社,1988． 66～75 Li L,Jin G Y.Lithospheric electricity structure in Panxi region.In:Selection of Papers on the Panxi Rift(in Chinese).Beijing:Geological Publishing House,1988,(3) :66～75
[25] Langston C A.Structure under Mount Rainier,Washington,inferred from teleseismic body waves.J.Geophys.Res.,1979,84:4749～4762
[26] 胡家富,苏有锦,朱雄关等.云南的地壳s波速度与泊松比结构及其意义.中国科学(D辑),2003,33(3) :714～722 Hu J F,Su Y J,Zhu X G,et al.S-wave velocity and Poisson's ratio structure of crust Yunnan and its implication.Sci.China(D)(in Chinese),2003,33(8) :714～722
[27] 胡家富,朱雄关,夏静瑜等.利用面波和接收函数联合反演滇西地区壳幔速度结构.地球物理学报,2005,48(5) :1069～1076 HuJ F,Zhu X G,Xia J Y,et al.Using surface wave and receiver function to jointly inverse the crust-mantle velocity structure in the West Yunnan area.Chinese J.Geophys.(in Chinese),2005,48(5) :1069～1076
[28] England P C,Mc Kenzie D P.A thin viscous sheet model for continental deformation.Geophys.J.R.Astro.Soc.,1992,70:295～321
[29] England P C,Houseman G A.Finite strain calculations of continental deformation,1． Application to the India-Asia collision zone.J.Geophys.Res.,1986,91:3664～3676
[30] England P C,Houseman G A.Extension during continental convergence,with application to tbe Tibetan Plateau.J.Geophys.Res.,1989,94:17561～17579
[31] Houseman G A,England P C.Finite strain calculation of continental deformation,1． Method and general results for convergent zones.J.Geophys.Res.,1986,91:3651～3663
[32] Clark M K,Royden L H.Topographic ooze:Building the eastern margin of Tibet by lower crustal flow.Geology,2000,28:703～706
[33] Clark M K,Bush J W M,Royden L H.Dynamic topography produced.by lower crustal {low against rheological strength heterogeneities bordering the Tibetan Plateau.Geophy.J.Int.,2005,162:575～590
[34] Copley A,Mc Kenzie D P.Models of crustal flow in the India-Asia collision zone.Geophys.J.Int.,2007,169:683～698
[35] Zhu L P,Kanamori H.Moho depth variation in southern California from teleseismic receiver functions.J.Geophys.Res.,2000,105:2969～2980．
[36] Zhu L P,Owens T J,Randall G E.Lateral variation in crustal structure of the northern Tibetan plateau inferred from teleseismic receiver functions.Bull.Seismol.Soc.Am.,1995,85(6) :1531～1540．
[37] Hayes G P,Furlong K P.Abrupt changes in crustal structure beneath the Coast Ranges of northern California developing new techniques in receiver {unction analysis.Geophys.J.Int.,2007,170:313～336
[38] Savage M K.Lower crustal anisotropy or dipping boundaries? Effects on receiver functions and a case study in New Zealand.J.Geophys.Res.,1998,103:15069～15087
[39] 吴庆举,曾融生.用宽频带远震接收函数研究青藏高原的地壳结构.地球物理学报,1998,41(5) :669～679 Wu Q J,Zeng R S.The crustal structure of Qinghai-Xizang Plateau inferred from broadband teleseismic waveform.Chinese J.Geophys.(in Chinese),1998,41(5) :669～679
[40] 李永华,吴庆举,田小波等.青藏高原拉萨及羌塘块体的地壳结构研究.地震学报,2006,28(6) :586～595 Li Y H,Wu Q J,Tian X B.The crustal structure beneath Qiangtang and Lhasa terrane from receiver function.Acta Seismologica Sinica(in Chinese),2006,28(6) :586～595
[2] 许忠淮.东亚地区现今构造应力图的编制.地震学报,2001,23(5) :492～501 Xu Z H.A present-day tectonic stress map for eastern Asia region.Acta Seismologica Sinica(in Chinese),2001,23(5) : 492～501
[3] Qin C,Papazachos C,Papadimitriou E.Velocity field for crustal deformation in China derived from seismic moment tensor summation of earthquakes.Tectono Physics,2002, 359:29～46
[4] 王琪,赖锡安,游新兆等.红河断裂的GPS监控与现代构造应力场.地壳变形与地震,1998,18(2) :49～56 Wang Q,Lai X A,You X Z,et al.GPS movement and present tectonic stress field in the Honghe fault,southwest China.Crustal Deformation and Earthquakes(in Chinese), 1998,18(2) :49～56
[5] Wang Q,Zhang P Z,Freymueller J T,et al.Present day crustal deformation in China constrained by global positioning system measurements.Science,2001,294:574～577
[6] 张培震,沈正康,王敏等.青藏高原及周边现今构造变形的运动学.地震地质,2004,26(3) :367～376 Zhang P Z,Shen Z K,Wang M,et al.Kinematics of present-day tectonic deformation of the Tibetan Plateau and its vicinities.Seismology and Geology(in Chinese),2004, 263:367～376
[7] Wang C Y,Chan W W,Mooney W D.Three-dimentional velocity structure of crust and upper mantle in southeastern China and its tectonic implications.J.Geophys.Res.,2003, 108(B9) ,2442,doi:10． 1029/2002JB001973
[8] Xu L L,Rondenay S,van der Hilst R D.Structure of the crust beneath the southeastern Tibetan Plateau from teleseismic receiver functions.Phys.Earth Planet.Int., 2007,165:176～193
[9] Owens T J,Zandt G.Implications of crustal property variations for models of Tibetan plateau evolution.Nature, 1997,387:37～43
[10] 滕吉文,张中杰,王光杰等.喜马拉雅碰撞造山带的深层动力过程与陆-陆碰撞新模型.地球物理学报,1999,42(4) :481～495 Teng J W,Zhang Z J,Wang G J,et al.The deep internal dynamical processes and new model of continental continental collision in Himalayan collision orogenic zone.Chinese J.Geophys.(in Chinese),1999,42(4) :481～495
[11] 刘启元,Rainer Kind,李顺成.中国数字地震台网的接收函数及其非线性反演.地球物理学报,1 997,40(5) :356～368 Liu Q Y,Rainer Kind,Li S C.The receiver functions at the stations of the Chinese Digital Seismic Network(CDSN)and their nonlinear inversion.Chinese J.Geophys.(Acta Geophysica Sinica)(in Chinese),1997,40(5) :356～368
[12] 吴庆举,曾融生,赵文津.喜马拉雅-青藏高原的上地幔倾斜构造与陆-陆碰撞过程.中国科学(D辑),2004,34(10) :919～925 Wu Q J,Zeng R S,Zhao W J.Upper mantle dipping tectonics and continent continent collision process in Himalayan-Tibet.Science in China(Set.D)(in Chinese),2004,34(10) :919～925
[13] 段永红,张先康,刘志等.阿尼玛卿缝合带东段地壳结构的接收函数研究.地震学报,2007,29(5) :483～491 Duan Y H,Zhang X K,Liu Z,et al.Crustal structure using receiver function in the east part of Anyemaqen suture belt. Acta Seismologica Sinic(in Chinese),2007,29(5) :483～491
[14] Burchfiel B C,Chen Z,Liu Y,et al.Tectonics of the Longmen Shan and adjacent regions.Int.Geol.Rev.,1996． 37:661～735
[15] King R W,SHEN Feng,Bruchfiel B C,et al.Geodetic measurement of crustal motion in southwest China.Geology,1997,25,1279～1282
[16] Chen Z,Burchfiel B C,Liu Y,et al.Global positioning system measurements from eastern Tibet and their implications for India/ Eurasia intercontinental deformation.J.Geophys.Res.,2000,105(B7) :16215～16227
[17] Shen F,Royden L H,Burchfiel B C.Large-scale crustal deformation of Tibetan Plateau.J.Geophys.Res.,2001,106:6793～6816
[18] Lev E,Long M D,van der Hilst R D.Seismic anisotropy in Eastern Tibet from shear wave splitting reveals changes in lithospheric deformation.Earth Planet.Sci.Lett.,2006,251:293～304
[19] Flesch L M,Holt W E,Silver P G,et al.Constraining the extent of crust-mantle coupling in central Asia using GPS,geologic,and shear-wave splitting data.Earth Planet.Sci.Lett.,238(1/2) :248～268
[20] 熊熊,滕吉文.青藏高原东缘地壳运动与深部过程的研究.地球物理学报,2002,45(4) :507～514 Xiong X,Teng J W.Study on crustal movement and deep process in eastern Qinghai-Xizang Plateau.Chinese J.Geophys.(in Chinese),2002,45(4) :507～514
[21] 吴乾蕃,祖金华,谢毅真等.云南地区地热基本特征.地震地质,1988,10(4) :177～183 Wu Q F,Zu J H,Xie Y Z.Basic geothermal characteristics in Yunnan Province.Seismol.Geol.(in Chinese),1988,10(4) :177～183
[22] 熊熊,谢厚泽,滕吉文.青藏高原物质东流力学背景探讨.地壳形变与地震,2001,21(2) :1～7 Xiong X,Xie H Z,Teng J W.Investigation for the mechanical background of the mass eastern flow in Tibetan Plateau.Crustal Deformation and Earthquakes(in Chinese),2001,21(2) :1～7
[23] 孙洁,徐常芳,江钊等.滇西地区地壳上地幔电性结构与地壳构造活动的关系.地震地质,1989,11(1) :35～45 Sun J,Xu C F,Jiang Z,et al.The electrical structure of the crust and upper mantle in the west part of Yunnan provinec and its relation to crustal tectonics.Seismol.Geol.(in Chinese),1989,11(1) :35～45
[24] 李立,金国元.攀西地区岩石圈的电性结构.见:中国攀西裂谷文集(3) .北京:地质出版社,1988． 66～75 Li L,Jin G Y.Lithospheric electricity structure in Panxi region.In:Selection of Papers on the Panxi Rift(in Chinese).Beijing:Geological Publishing House,1988,(3) :66～75
[25] Langston C A.Structure under Mount Rainier,Washington,inferred from teleseismic body waves.J.Geophys.Res.,1979,84:4749～4762
[26] 胡家富,苏有锦,朱雄关等.云南的地壳s波速度与泊松比结构及其意义.中国科学(D辑),2003,33(3) :714～722 Hu J F,Su Y J,Zhu X G,et al.S-wave velocity and Poisson's ratio structure of crust Yunnan and its implication.Sci.China(D)(in Chinese),2003,33(8) :714～722
[27] 胡家富,朱雄关,夏静瑜等.利用面波和接收函数联合反演滇西地区壳幔速度结构.地球物理学报,2005,48(5) :1069～1076 HuJ F,Zhu X G,Xia J Y,et al.Using surface wave and receiver function to jointly inverse the crust-mantle velocity structure in the West Yunnan area.Chinese J.Geophys.(in Chinese),2005,48(5) :1069～1076
[28] England P C,Mc Kenzie D P.A thin viscous sheet model for continental deformation.Geophys.J.R.Astro.Soc.,1992,70:295～321
[29] England P C,Houseman G A.Finite strain calculations of continental deformation,1． Application to the India-Asia collision zone.J.Geophys.Res.,1986,91:3664～3676
[30] England P C,Houseman G A.Extension during continental convergence,with application to tbe Tibetan Plateau.J.Geophys.Res.,1989,94:17561～17579
[31] Houseman G A,England P C.Finite strain calculation of continental deformation,1． Method and general results for convergent zones.J.Geophys.Res.,1986,91:3651～3663
[32] Clark M K,Royden L H.Topographic ooze:Building the eastern margin of Tibet by lower crustal flow.Geology,2000,28:703～706
[33] Clark M K,Bush J W M,Royden L H.Dynamic topography produced.by lower crustal {low against rheological strength heterogeneities bordering the Tibetan Plateau.Geophy.J.Int.,2005,162:575～590
[34] Copley A,Mc Kenzie D P.Models of crustal flow in the India-Asia collision zone.Geophys.J.Int.,2007,169:683～698
[35] Zhu L P,Kanamori H.Moho depth variation in southern California from teleseismic receiver functions.J.Geophys.Res.,2000,105:2969～2980．
[36] Zhu L P,Owens T J,Randall G E.Lateral variation in crustal structure of the northern Tibetan plateau inferred from teleseismic receiver functions.Bull.Seismol.Soc.Am.,1995,85(6) :1531～1540．
[37] Hayes G P,Furlong K P.Abrupt changes in crustal structure beneath the Coast Ranges of northern California developing new techniques in receiver {unction analysis.Geophys.J.Int.,2007,170:313～336
[38] Savage M K.Lower crustal anisotropy or dipping boundaries? Effects on receiver functions and a case study in New Zealand.J.Geophys.Res.,1998,103:15069～15087
[39] 吴庆举,曾融生.用宽频带远震接收函数研究青藏高原的地壳结构.地球物理学报,1998,41(5) :669～679 Wu Q J,Zeng R S.The crustal structure of Qinghai-Xizang Plateau inferred from broadband teleseismic waveform.Chinese J.Geophys.(in Chinese),1998,41(5) :669～679
[40] 李永华,吴庆举,田小波等.青藏高原拉萨及羌塘块体的地壳结构研究.地震学报,2006,28(6) :586～595 Li Y H,Wu Q J,Tian X B.The crustal structure beneath Qiangtang and Lhasa terrane from receiver function.Acta Seismologica Sinica(in Chinese),2006,28(6) :586～595
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